PROJECT SUMMARY Guided by Taplin et al.?s model of multilevel influences of the cancer care continuum, the proposed project investigates how state health policies and provider-level factors influence human papillomavirus (HPV) vaccination among sexual and racial/ethnic minority women. The project?s two specific aims are to: (1) examine the effect of state Medicaid expansions and HPV vaccine policies on HPV vaccination initiation among sexual and racial/ethnic minority U.S. women aged 15-25 years and (2) explore health care providers? beliefs, attitudes, decision-making processes, and practices related to HPV vaccination among adolescent and young adult sexual and racial/ethnic minority women. I will address Aim 1 by using state-level data from the National Conference of State Legislatures and individual-level 2011-2015 National Survey of Family Growth data to conduct a difference-in-difference analysis that uses multivariable linear regression to assess the association between the implementation of state Medicaid expansions and HPV vaccine policies and the proportion of U.S. women aged 15-25 years who initiated HPV vaccination in relation to both sexual orientation identity and race/ethnicity (separately). I will address Aim 2 by conducting 30 in-depth interviews with health care providers selected using a purposive sampling approach and recruited from four Boston-area community health centers that provide care to underserved populations. I will analyze the provider interview transcripts using immersion/crystallization, the template organizing style of qualitative data analysis, discourse analysis, and within- and cross-case analysis. By engaging in mentored research with Dr. Deborah Bowen (Mentor) and collaborators, completing coursework, and participating in seminars, conferences, and regular mentoring meetings, I will develop expertise in three new areas critical to my development as an interdisciplinary, independent investigator who examines how factors at not only the patient but also the provider and policy levels influence cancer screening and prevention disparities: health services research, health policy, and advanced econometrics. Moreover, I will extend my grant writing and oral presentation skills by participating in grant writing courses and presenting at research meetings and seminars. The Harvard T.H. Chan School of Public Health offers junior scholars with the intellectual and practical resources they need to develop into successful independent investigators, including junior faculty seminars, grant writing, editing, and review services, and opportunities for intellectual exchange and collaboration with senior colleagues. A K01 award will provide me with the research experience, skills, and mentorship I need to build a cutting-edge independent research program that examines how factors at the patient, provider, and policy levels influence the utilization of cervical and other cancer prevention and screening services among underserved U.S. women and men.